When a vehicle having a fuel cell system mounted thereon is running across an area with low air density such as a highland, for example, the rotational speed of the compressor supplying a fuel cell with air (oxidation gas) is kept high even while the vehicle is idling during a temporary stop. Accordingly, there may be a rise of the temperature of oil for lubricating and cooling the bearing of the compressor and the gear, which may lead to occurrence of failure.
Patent Literature 1 describes limiting the operation of an oxidation gas supply means under a low-air-density environment. However, Patent Literature 1 is directed to controlling the upper limit of the rotational speed of the compressor to reduce noise when air pressure has decreased, and does not refer to failure that may occur in the system.
In addition, Patent Literature 2 describes controlling the hydrogen pressure to adjust the pressure of the fuel cell and also limiting the output of the compressor. However, Patent Literature 2 does not disclose measures to be taken when air pressure has decreased.